Hi, On Tue, Mar 16, 2010 at 03:10:37, Andrew Morton wrote: > On Fri, 12 Mar 2010 18:04:09 +0530 > Sudhakar Rajashekhara <sudhakar....@ti.com> wrote: > > > On some platforms like DM355, the number of EDMA parameter > > slots available for EDMA_SLOT_ANY usage are few. In such cases, > > if MMC/SD uses 16 slots for each instance of MMC controller, > > then the number of slots available for other modules will be > > very few. > > > > By passing the number of EDMA slots to be used in MMC driver > > from platform data, EDMA slots available for other purposes > > can be controlled. > > It's unclear what the runtime effects of this change are. I assumed > (without justification) that they're minor and I scheduled the patch for > 2.6.35. > > If that was the wrong decision then blame the changelog ;) >
Most of the platforms will not use this platform data variable. But on DM355, as the number of EDMA resources available is limited, the number of scatter- gather segments used inside the MMC driver can be 8 (passed as platform data) instead of 16. On DM355, when the number of scatter-gather segments was reduced to 8, I saw a performance difference of about 0.25-0.4 Mbytes/sec during write. Read performance variations were negligible. Thanks, Sudhakar _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
